Toroid choke question

[okkyn]

Hi all,

I have curiousity, among toroid chokes in the market, do they use air gapped toroid core or they employ special winding techniques?

I ask this because I have several toroid cores and I have plan to make choke out of them if possible.

TIA,
okkyn

[Rocky]

Can't you get something other than toroids to make chokes of, and make push-pull or parafeed OPTs or other signal iron from the toroids? Toroids are really far from ideal for chokes.. I think they actually use gapped toroids at plitron BTW. I could be wrong.

[poobah]

okkyn,

Many toroids are actually a ceramic. Ferrite is one type of ceramic. Ferrite is a actually a family of materials. There are many different types. Ferrites have much lower permeability. so they say the gap is "distributed". That is too say, a million little gaps in the material.

These are popular for small value inductors that operate at high frequency.

Other toroids are "tape wound". The shape is formed by winding a thin strip of metal into a coil. The have permeabilies similar to standard transformers. They have high permeability and are used where high values of inductance is required.

Why ferrite you ask? Because ferrite can operate with high efficiency at high frequencies. The ferrite material does not conduct so well... eddy currents are greatly reduced.

So to answer your question, if you have a tape wound core, you could make a gap or slot.

If you have a ferrite core... it already has a gap (in the material). You couldn't cut it anyway without diamond tools anyway.

[okkyn]

Thanks guys for the information.

I have no problem using chokes other than toroids, just it looks pleasing to my eyes (combined with toroid OPTs and power)

okkyn